In pathology industries samples from different sources need to be analysed for different reasons. Some of the samples may also need to be split or apportioned for multiple analysis. It is desired to automate the distribution systems for these samples so that there is minimum human involvement in the distribution.
For example, the collection and analysis of samples including pathology specimens such as blood involve numerous steps which are prone to human errors. The errors could result in disastrous consequences for both the medical laboratory and the patients concerned. One fundamental area where such errors can occur is the transfer of the specimen from primary specimen tubes containing the specimen first collected from a patient to secondary sample tubes which thereby contain aliquot of the specimen for actual analysis by an analysing instrument. Major problems occur where the tubes are incorrectly labelled or the tubes are of an incorrect type for a particular test specifically requisitioned by a physician. In order to solve these and other problems, most pathology laboratories have in place numerous time consuming manual checking procedures. As a consequence of the advent of highly contagious and dangerous diseases such as AIDS and hepatitis and advances in computer technology, much of the organisation and transfer of the secondary sample tubes to racks or holders for the purpose of analysis is now substantially automated. The whole process is often monitored to an extent such that an enquiry of the computer system involved will reveal the location of the primary specimen tubes and/or secondary sample tubes at any stage of the tube management and analytical process.
Invariably, pathology specimen distribution centres are often placed invidiously in what can only be described as a “meat in the sandwich” situation. This may be given by way of example where a distribution centre has to decide which test is appropriate when the full spectrum of test procedures is not known or understood by a referring physician, or, when a scientist responsible for the analytical procedures has not clearly spelt out to specimen collecting staff what type and amount of specimen are required. This situation is often resolved by obtaining further specimens from the patient.
This practice is wasteful of time and resources such as disposable and extra specimen tubes or containers. The possibility of errors in such situations is often further compounded by the limitations of the laboratory's computer information management system (LIMS) which is only as accurate as the information provided to it.
Many laboratories continue to employ a manual specimen tube management system because their primary focus is in the analysis of samples and the actual reporting of the analysis results. Unless the laboratory has an automated specimen distribution system, human errors can easily occur in any manual specimen tube management system which are often to the detriment of other areas of the analysis. As a consequence of the absence of an accurate fail safe tube management system, it may be impossible to know if a correct specimen type has been collected until it is delivered to the scientist at the analyser. The scientist will also have to decide at this stage whether a sufficient sample volume has been collected for the particular analysis and whether or not the sample, for example if it is blood, is too haemolysed or clotted for a particular test to be carried out. As a result many of the errors found in laboratories have their origin at the specimen distribution centre and such errors become compounded as the laboratory process continues. Further the absence of automated tube management systems often leads to inefficient manual sample storage facilities resulting in the misplacement of samples received so that the result obtained if inconsistent with what is expected has to be rechecked by re-running the test against a reference source to verify the particular infection. In laboratories where there are no reliable sample storage systems, there is usually a proliferation of various systems which are not under computer control resulting in unnecessary costs including resources and consumables for further tests as mentioned above.
In attempting to identify these and other problems, the applicant has listed a number of deficient areas found in current manual systems and those systems necessarily involving other instruments and tests. Some of these deficiencies include the transportation of uncapped primary and secondary tubes resulting in the increased possibility of contamination. The fact that the same specimen can be collected in different tube types having different colour coded caps can also result in confused or erroneous readings by instruments or staff unfamiliar with a particular manufacturer's colour coding scheme.
In addition, the presence of different cap types and different clot activating substances being used by different physicians for collected blood specimens can cause the laboratory to restrict itself to one collection tube manufacture in the interest of eliminating errors.
Furthermore, the particular tube transport mechanism associated with a specific test often dictates the design of the laboratory and results in restricting the tube management system to one analysis type only.
Other limitations include the inability to distribute samples from one collection resulting in multiple collections of the same specimen type where it is necessary to repeat the same test or where other tests on the same type of specimen are involved.
Known attempts to overcome certain of the above problems include a number of systems presently in operation which may be broadly categorised as follows:—    1. An existing manually controlled system is modified by taking advantage of various analysers that are capable of bar code reading and manually interfacing them with the laboratory's existing computer information management system based on bar coding. This has often resulted in the collection of more specimens from the patients in order to distribute each separate collection tube to a specific analyser resulting in a wastage of specimen and problems associated where a great number of tubes have to be handled, for example, misplacement of sample tubes, accidental spillage and contamination.    2. Systems which utilise a conveyor belt that transports the collected specimen tubes to an appropriate work station where a tube is captured and acted upon by a number of processes inclusive of picking up the tube and putting it in a storage rack. The system then recaps the specimen tubes and transports the capped tubes to their destination. In this system there is no computerised management system so that each laboratory has to write its own manually controlled management system in respect of the whole process.    3. Systems which utilise the conveyor belt system but are limited by utilising one manufacturer's specimen tube type only. This system processes the specimen by the tipping the collection tube in an inverted position, inserting a disposable plastic device into the specimen tube and then pumping in air to expel a sample of the specimen to a secondary tube of a certain type.    4. Systems which use a robotic arm to uncap and distribute specimen tubes in which the primary specimen is collected without any distribution or transfer of sample amounts or aliquot to secondary tubes.    5. Systems which utilise a needle to pierce the cap of the primary specimen tube and distribute sample aliquot to unlabelled and uncapped secondary tubes in a rack that holds all the tubes associated with the particular primary specimen tube.
Specific problems which have been identified by the applicant associated with the prior art systems described above include the following:    1. Conveyor belt systems are large and bulky and often cut across doorways and require major remodelling and restructuring of the laboratory.    2. Prior art tube distribution systems are often restricted to primary specimen tubes and secondary sample tubes of a certain type or make. Where specimen and/or sample tubes not of the type associated with the particular prior art system are used, this can result in breakages of the tubes during processing resulting in the loss of the specimen and/or contamination of apparatus.    3. There is often an absence of an on board computerised tube monitoring facility to keep track of the physical status of the tubes which can result in exposure to uncapped tubes causing contamination of the sample as well as the laboratory environment.    4. Systems where the available sample volume is not measured prior to the aspiration of the sample resulting in the situation that multiple samples cannot be obtained from the single specimen for example where one tube of blood is insufficient for the battery of tests requested and therefore two or more samples have to be further collected.    5. Systems which are restricted to certain types of specimens such that the systems are not able to cope with specimens of serum, plasma, urine and other fluids from a single patient.    6. Systems where the recapping of primary specimen tubes are made with another cap resulting in higher running costs and design constraints which may result in spillage and the possibility of contamination when a tube is broken or dropped due to the extra handling of the tube associated with the recapping process.    7. A restriction on rack types or holders required by separate analysing instrument systems.    8. The absence of systems where there is an automated labelling of the secondary sample tubes resulting in an increased chance of human errors.    9. Systems where the cost effective sealing of secondary tubes by the use of plastic laminate instead of caps is not provided for.    10. Systems which cannot identify the physical characteristics of a particular specimen tube and/or the specimen in the tube prior to processing.    11. Systems which cannot process more than one type of primary specimen tube or secondary sample tube as previously described.